Composites are increasingly used in aerospace technology as a replacement for metals. In airplanes and helicopters, composites are an improvement over metals as they are lightweight, strong, durable and can be manufactured economically. Many aircraft composite components are comprised of sandwich structures having two composite skins surrounding a filler material (e.g., honeycmmb, foam).
In many applications, composite sandwiches must be joined together. There are a variety of joints that may be used. FIGS. 1 and 2 illustrate common bonded joints involving single and double overlaps, respectively. Although these bonds can be adequate for some applications, both examples have a a large reduction in bending stiffness across sections A--A and B--B. Although the double overlap design has twice the effective bond length as the single overlap, it is extremely difficult to fabricate.
Accordingly, there has been a constant search in the field of aircraft composite components for joints having improved strengths to withstand axial loads as well as bending loads.